Centerless grinding machine

ABSTRACT

The centerless grinding machine includes a grinding head in fixed position. The infeed and outfeed bar roll assemblies and the regulating wheel and bar rest assembly are movable toward and from the grinding element in the grinding head. An in-process grinding wheel guaging device is provided for continuously gauging the diameter of the wheel. As the wheel wears, during the grinding operation, the gauge signals the amount of wear to a numerical control system which effects movement of the roll assemblies, and the regulating wheel and rest assembly toward the grinding wheel to compensate for the wheel wear. The bar loading assembly may also be moved under the control of the wheel gauge.

United States Patent Schaller [451 Aug. 22, 1972 [54] CENTERLESS GRINDING MACHINE [72] Inventor: Robert L. Schaller, 5118 Munro Rd., Camillus, NY. 13031 [73] Assignee: Sunstrand-Engelberg, Inc.

[22] Filed: April 16, 1970 [21] Appl. No; 29,031

[52] US. Cl ..5l/103 TF, 51/139, 51/165.88, 51/215 H [51] Int. Cl. ..B24b 5/18 [58] Field of Search.5l/l03 TF, 103 R, 139, 165.87, 5l/l65.88,215 H [56] References Cited UNITED STATES PATENTS 1,814,367 7/1931 Caster ..'...51/103 TF 2,647,347 8/1953 Blanchette ..51/103 R X 3,466,810 9/1969 Schaller ..51/238 R 3,503,156 3/1970 Schaller ..5 H103 R X 3,503,159 3/1970 Schaller ..5 H103 R X 3,541,735 11/1970 Schaller et a1. ..5l/139 3,571,981 3/1971 Schaller ..5 H139 X Primary Examiner--bester M. Swingle Attorney-D. Emmett Thompson [57] ABSTRACT The centerless grinding machine includes a grinding head in fixed position. The infeed and outfeed bar roll assemblies and the regulating wheel and bar rest assembly are movable toward and from the grinding element in the grinding head. An in-process grinding wheel guaging device is provided for continuously gauging the diameter of the wheel. As the wheel wears, during the grinding operation, the gauge signals the amount of wear to a numerical control system which effects movement of the roll assemblies, and the regulating wheel and rest assembly toward the grinding wheel to compensate for the wheel wear. The bar loading assembly may also be moved under the con-' trol of the wheel gauge.

7 Clains, 4 Drawing Figures PATENTEDmszz m2 SHEET 1 BF 3 INVENTOR.

ROBERT L. SCHALLER. BY

ATTORNEY.

CENTERLESS GRINDING MACHINE BACKGROUND OF THE INVENTION Centerless grinding machines have been provided with means for dressing the grinding wheel, and with means for moving the regulating wheel toward the grinding wheel to compensate for the reduction in diameter of the grinding wheel due to the dressing operation. While this arrangement establishes a predetermined spacing between the grinding wheel and the regulating wheel for the intended purpose of grinding bars uniformly to a desired diameter, the arrangement is not satisfactory to maintain the desired bar diameter within close tolerances. Such an arrangement does not automatically and continuously effect a comparable adjustment of the feed rolls supporting the bar during its axial movement into and through the throat of the machine, nor does such an arrangement effect automatic adjustment of the work rest.

BRIEF SUMMARY OF THE INVENTION This invention has as an object a centerless grinding machine wherein the diameter of the grinding wheel is continuously gauged. The various components of the machine having to do with the positioning of the bar, such as the in-feed rolls, work rest and regulating wheel are initially zeroed from a signal produced by the wheel gauge and thereafter, all of these components are adjusted in unison, as by numerical control, for the grind ing of a bar of specified diameter to effect uniform grinding of the bar to a pre-selected precise diameter.

The invention includes an arrangement whereby the various components of the machine are adjusted during the grinding of the bar to compensate for wheel wear, all whereby the specified bar diameter is constantly maintained.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a front elevational view illustrating a machine embodying my invention.

FIG. 2 is an end elevational view looking to the left, FIG. 1.

FIG. 3 is a view taken on line 3-3, FIG. 1.

FIG. 4 is a schematic diagram of the circuity for controlling the various components of the machine.

DETAILED DESCRIPTION toward and from the grinding element 17. The slide is guided by ways 21. The movement of the slide may be effected by a lead screw 23 driven by a servo motor 24.

Fixedly mounted on the inner end of the slide is a work rest supporting structure 25 in which a work rest 26 is mounted for vertical adjustment. The support 25 I may contain screw jack structure operated by a servo motor 27 to effect vertical adjustment of the work rest 26 toward and from the axis of the bar 30. Such a work rest adjusting structure is disclosed in US. Pat. No. 3,466,810, issued Sept. 16, 1969.

The slide 20 is provided with ways 33 in which a regulating wheel mechanism 35 is mounted for sliding movement toward and from the work rest 26. The regulating wheel mechanism includes a power driven regulating wheel 37, FIG. 2. Sliding movement to and from the work rest 26 is imparted to the regulating wheel 35 by a screw 40 operated by a servo motor 41. The motors 24, 41, may be provided with read-out devices 45. While the regulating wheel mechanism 35 is adjustable by motor 41, and the rest 26 is adjusted by motor 27, it will be apparent both the regulating wheel and the rest are adjusted as an assembly by motor 24 actuating the slide 20.

Referring to FIGS. 1 and 3, the in-feed roll assembly includes base beams 50 secured to the plate 13. The structure includes columns 51 of substantial height, and short columns 53 spaced rearwardly of the columns 51 are positioned on beams 50. The columns 51, 53, are connected by members 55 and 57. Pads 58 are secured to the lower ends of the columns 51, 53, and are arranged in gibs 60 for sliding movement on the beams 50 for movement in a direction transverse to the axis of the bar 30 being ground. A cross beam 63 is fixed to the upper ends of the columns 51, and serves to support a plurality of housings 65. A ram 67 is slidably mounted in each of the housings 65, sliding movement being imparted to the rams through a worm gear transmission mounted in each housing and actuated by a shaft 68. The shafts 68 are connected by shafts 70 driven by a servo motor 71.

A bifurcated yoke member 73 is fixed to each of the rams 67, and a feed roll 75 is joumalled in each of the yokes 73. The rams 67 and the feed rolls 75 carried thereby are moved in a horizontal plane toward and from the axis of the bar being ground by the motor 71.

Beams are fixed to the beam 81 extending between the upright posts 51. The beams 80 extend rearwardly to inclined beams 83, FIG. 3, which are supported by the beams 57. A plate 85 is fixed to the inclined beams 83. Screw jack structures are mounted on the plate 85 and arranged in registration with the housings 65. The units 90 are of the same structural arrangement as the units 65, including the yokes 91, in each of which is joumalled a roll 92. The shafts of the jack structures in the housings 90 are operated by a servo motor 97, FIG. 1. Rotation of the shafts 95 effects movement of the rolls 92 toward and from the axis of the bar 30. Simultaneous operation of the shafts 68, 95, efiects movement of the rolls 75, 92, to accept work bars 30 of different diameters. The numerical control system connected to the motors 71, 97, effects movement of the rolls 75, 92, to maintain work bars of different diameters with their axes positioned on the same pass line.

Initially, in operation, the numerical control system functions 'to adjust the regulating wheel 37, the work 'rest 26, and the in-feed rolls 75, 92, to accept a work bar 30 of a selected diameter and position the bar on a preselected axis to effect grinding of the work bar to a desired diameter.

During the operation of the machine, it will be appreciated that the grinding element 17 wears away and accordingly, is reduced in diameter, thereby increasing the spacing between the grinding wheel and the regulating wheel 37. In order to maintain the desired finished diameter of the work bar, the regulating wheel 37 is moved inwardly toward the grinding wheel 17 a distance to compensate for the reduction of the diameter of the grinding wheel.

The diameter of the grinding wheel is constantly gauged by a gauging element 100 fixedly mounted on the grinding head for continuous contact with the periphery of the grinding wheel.

A position setter 105, FIG. 4, is operated according to the diameter of the finished ground bar. The position setter 105 transmits a signal over line 106 to an amplifier 107, the output of which is transmitted to a position read-out device 108, and from there to an actuator device 110, the output from which is transmitted to the servo motors 71, 97, to effect movement of the in-feed rolls 75, 92, to correctly position the bar of the selected diameter. The signal from line 106 is transmitted to an amplifier 111 having an output extending through a position read-out 112 and an actuator 113, to provide actuating power to the motor 41 to effect movement of the regulating wheel 37 to the proper position for the selected bar.

In like manner, the signal from line 106 is fed to an amplifier 115, the output being connected through a position read-out 116, to an actuator 117 connected to the motor 27 which functions to properly position the rest 26. The signal from line 106 is also fed to an amplifier 120, the output of which is transmitted through the position read-out 121 and actuator 122 to the servo motors 126, 130.

The bars are automatically transferred from a load rack 131, FIG. 3, by mechanism including a series of bar transfer arms 132. The loading rack 131 is supported on columns 133 which, like the columns 51, 53, are slidably mounted on the beams 50. The infeed wheel assembly is moved in a direction lengthwise of the beams 50 that is, transversely to the axis of the bar 30, by screw jack mechanism 134, FIG. 3, actuated by the servo motor 126, FIG. 1. Also in the arrangement shown, the bar supporting rack is moved by a screw jack mechanism 135 powered by the servo motor 130.

The signal from line 106 is fed through an amplifier 140, position read-out 141, actuator 142, to motor 24. It will be recalled that motor 24 effects movement of slide which carries the regulating wheel and rest assembly. The signal from the wheel gauging device 100 is fed through a power amplifier 145 to the amplifier 120. Also, the gauging signal is fed to the amplifier 140. Accordingly, when the position setter 105 is dialed for a bar of given diameter, the in-feed rolls 75, 92, the regulating wheel 37 and the bar rest 26, are individually moved to position the bar on the pass line. Also, the regulating wheel and the rest assembly is positioned in respect to the then diameter of the grinding wheel 17. Also the in-feed roll assembly and the loading rack are positioned in respect to the grinding wheel diameter. While the signal from line 106 is effective to operate motors 24, 126, 130, to move the above assemblies to a theoretically correct position for the bar diameter dialed in, the signal from line 106 is modified by the signal from the wheel gauge to accurately position the assemblies in respect to the then diameter of the wheel 17. The signal from line 106 is constantly modified by the wheel gauging device to move the infeed roll assembly, the regulating wheel, rest assembly, and the bar loader, in proportion to the wheel wear.

What I claim is:

l. A centerless bar grinding machine comprising a base, a grinding head fixedly mounted on said base and having a rotatable power driven generally cylindrical grinding element having an axis of rotation, a diameter and a periphery, a slide mounted on said base for movement toward and from the axis of said grinding element, a bar rest mounted on said slide, a regulating wheel assembly mounted on said slide for movement independently thereof toward and from the axis of rotation of said grinding element to accommodate generally cylindrical bars of different diameters, each having an axis of rotation, means mounting said rest on said slide intermediate said head and regulating wheel assembly for adjustment toward and from the axis of rotation of the bar being ground, an in-feed roll structure including a frame mounted on said base for movement toward and from the axis of said grinding element, a linear series of feed roll assemblies mounted on said frame for adjustment to accommodate bars of different diameters, gauging means mounted in juxtaposition to the periphery of said grinding element, said gauging means being operable to continuously sense the diameter of said grinding element and transmit a signal indicative thereof, servo mechanism operable upon receipt of a signal from said gauging means indicative of a reduction of diameter of said grinding element to efiect proportional movement of said frame and said slide toward the axis of said grinding element.

2. A centerless bar grinding machine as set forth in claim 1, wherein said servo mechanism is operable upon receipt of said signal from said gauging means to effect simultaneous proportional movement of said frame and said slide.

3. A centerless bar grinding machine comprising a base, a grinding head fixedly mounted on said base and having a rotatable power driven generally cylindrical grinding element having an axis of rotation, a diameter and a periphery, a slide mounted on said base for movement toward'and from the axis of said grinding element, a bar rest mounted on said slide, a regulating wheel assembly mounted on said slide for movement independently thereof toward and from the axis of rotation of said grinding element to accommodate generally cylindrical bars of different diameters each having an axis of rotation, said rest being disposed intermediate said head and regulating wheel assembly and being adjustable toward and from the axis of rotation of the bar being ground, an in-feed roll structure including a first frame mounted on said base for movement toward and from the axis of said grinding element, a linear series of feed roll assemblies mounted on said first frame and being adjustable to accommodate bars of different diameters, a second frame mounted on said base for movement toward and from the axis of said grinding element, a bar supply rack carried by said second frame, a bar loading mechanism mounted on said second frame and operable to transfer bars successively from said supply rack to said feed roll assemblies,

gauging means fixedly mounted in juxtaposition to the periphery of said grinding element, said gauging means being operable to continuously sense the diameter of said grinding element and transmit a signal indicative thereof, servo mechanism operable upon receipt of a signal from said gauging means indicative of a reduction of diameter of said grinding element to effect proportional movement of said first frame, said second frame and said slide toward the axis of said grinding element.

4. A centerless bar grinding machine as set forth in claim 3, wherein said second frame is mounted on said base at the opposite side of the axis of said grinding element on which said first frame is mounted.

5. A centerless bar grinding machine comprising a base, a grinding head mounted on said base and having a rotatable power driven generally cylindrical grinding element having an axis of rotation, a diameter and a periphery, a slide mounted on said base for movement toward and away from the axis of said grinding element, a bar rest mounted on said slide, a regulating wheel assembly mounted on said slide for holding generally cylindrical bars against the grinding element, each bar having an axis of rotation, an in-feed roll structure including a first frame mounted on said base at one side of the axis of a bar in work position for movement toward and away from the axis of rotation of the grinding element and a linear series of feed roll assemblies mounted on said frame for advancing bars toward the grinding wheel, a second frame mounted on said base at the opposite side of the axis of rotation of a bar in work position for movement toward and away from the axis of said grinding element, including a bar supply mechanism associated with the feed roll assemblies, gauging means mounted adjacent the periphery of the grinding element to continuously sense the diameter of the grinding element and transmit a signal indicative thereof, and servo mechanism operable upon receipt of a signal from said gauging means indicative of a reduction of the diameter of said grinding element to efiect compensating adjustment of said slide, said first frame and said second frame relative to the axis of said grinding element.

6. A centerless bar grinding machine as defined in claim 5 wherein said second frame includes a bar supply rack and a bar loading mechanism operable to transfer bats successively from said bar supply rack to said feed roll assemblies.

7. A centerless bar grinding machine as defined in claim 5 including means mounting said bar rest on said slide intermediate said head and regulating wheel assembly for adjustment toward and away from the axis of rotation of a bar in work position, means mounting said regulating wheel assembly on said slide for movement independently thereof toward and away from the axis of said grinding element to accommodate bars of different diameters, and means mounting said feed roll assemblies on said first frame for adjustment toward and away from the axis of a bar in work position to accommodate bars of different diameters. 

1. A centerless bar grinding machine comprising a base, a grinding head fixedly mounted on said base and having a rotatable power driven generally cylindrical grinding element having an axis of rotation, a diameter and a periphery, a slide mounted on said base for movement toward and from the axis of said grinding element, a bar rest mounted on said slide, a regulating wheel assembly mounted on said slide for movement independently thereof toward and from the axis of rotation of said grinding element to accommodate generally cylindrical bars of different diameters, each having an axis of rotatioN, means mounting said rest on said slide intermediate said head and regulating wheel assembly for adjustment toward and from the axis of rotation of the bar being ground, an in-feed roll structure including a frame mounted on said base for movement toward and from the axis of said grinding element, a linear series of feed roll assemblies mounted on said frame for adjustment to accommodate bars of different diameters, gauging means mounted in juxtaposition to the periphery of said grinding element, said gauging means being operable to continuously sense the diameter of said grinding element and transmit a signal indicative thereof, servo mechanism operable upon receipt of a signal from said gauging means indicative of a reduction of diameter of said grinding element to effect proportional movement of said frame and said slide toward the axis of said grinding element.
 2. A centerless bar grinding machine as set forth in claim 1, wherein said servo mechanism is operable upon receipt of said signal from said gauging means to effect simultaneous proportional movement of said frame and said slide.
 3. A centerless bar grinding machine comprising a base, a grinding head fixedly mounted on said base and having a rotatable power driven generally cylindrical grinding element having an axis of rotation, a diameter and a periphery, a slide mounted on said base for movement toward and from the axis of said grinding element, a bar rest mounted on said slide, a regulating wheel assembly mounted on said slide for movement independently thereof toward and from the axis of rotation of said grinding element to accommodate generally cylindrical bars of different diameters each having an axis of rotation, said rest being disposed intermediate said head and regulating wheel assembly and being adjustable toward and from the axis of rotation of the bar being ground, an in-feed roll structure including a first frame mounted on said base for movement toward and from the axis of said grinding element, a linear series of feed roll assemblies mounted on said first frame and being adjustable to accommodate bars of different diameters, a second frame mounted on said base for movement toward and from the axis of said grinding element, a bar supply rack carried by said second frame, a bar loading mechanism mounted on said second frame and operable to transfer bars successively from said supply rack to said feed roll assemblies, gauging means fixedly mounted in juxtaposition to the periphery of said grinding element, said gauging means being operable to continuously sense the diameter of said grinding element and transmit a signal indicative thereof, servo mechanism operable upon receipt of a signal from said gauging means indicative of a reduction of diameter of said grinding element to effect proportional movement of said first frame, said second frame and said slide toward the axis of said grinding element.
 4. A centerless bar grinding machine as set forth in claim 3, wherein said second frame is mounted on said base at the opposite side of the axis of said grinding element on which said first frame is mounted.
 5. A centerless bar grinding machine comprising a base, a grinding head mounted on said base and having a rotatable power driven generally cylindrical grinding element having an axis of rotation, a diameter and a periphery, a slide mounted on said base for movement toward and away from the axis of said grinding element, a bar rest mounted on said slide, a regulating wheel assembly mounted on said slide for holding generally cylindrical bars against the grinding element, each bar having an axis of rotation, an in-feed roll structure including a first frame mounted on said base at one side of the axis of a bar in work position for movement toward and away from the axis of rotation of the grinding element and a linear series of feed roll assemblies mounted on said frame for advancing bars toward the grinding wheel, a second frame mounted on said base at the opposite side of the axis of rotation oF a bar in work position for movement toward and away from the axis of said grinding element, including a bar supply mechanism associated with the feed roll assemblies, gauging means mounted adjacent the periphery of the grinding element to continuously sense the diameter of the grinding element and transmit a signal indicative thereof, and servo mechanism operable upon receipt of a signal from said gauging means indicative of a reduction of the diameter of said grinding element to effect compensating adjustment of said slide, said first frame and said second frame relative to the axis of said grinding element.
 6. A centerless bar grinding machine as defined in claim 5 wherein said second frame includes a bar supply rack and a bar loading mechanism operable to transfer bars successively from said bar supply rack to said feed roll assemblies.
 7. A centerless bar grinding machine as defined in claim 5 including means mounting said bar rest on said slide intermediate said head and regulating wheel assembly for adjustment toward and away from the axis of rotation of a bar in work position, means mounting said regulating wheel assembly on said slide for movement independently thereof toward and away from the axis of said grinding element to accommodate bars of different diameters, and means mounting said feed roll assemblies on said first frame for adjustment toward and away from the axis of a bar in work position to accommodate bars of different diameters. 